There is often a need with electronic systems to generate desired amounts of jitter and/or wander in digital signals, for example, digital signals being used for test and measurement purposes.
Current techniques for generation of phase variation, such as jitter and/or wander, rely upon analog techniques. Some of these prior techniques are based on voltage controlled delay lines or a plurality of fixed delay lines or paths. Other such techniques are based on the use of voltage to adjust the frequency of an oscillator by increasing or decreasing the capacitance on nodes within the oscillator. Still other such techniques implement adjustable or selectable delay in PLL (phase locked loop) or DLL (delay locked loop) feedback circuits.
While these prior systems and techniques provide the ability to generate desired phase variation, such as wander and/or jitter, in resulting signals, it is desirable to be able to achieve improved resolution in generating desired phase variation in digital signals.